Update to 3.4-final.

[linux-flexiantxendom0-3.2.10.git] / mm / fadvise.c

diff --git a/mm/fadvise.c b/mm/fadvise.c
index a14b892..469491e 100644 (file)
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2002, Linus Torvalds
  *
- * 11Jan2003   akpm@digeo.com
+ * 11Jan2003   Andrew Morton
  *             Initial version.
  */
 
@@ -15,58 +15,146 @@
 #include <linux/backing-dev.h>
 #include <linux/pagevec.h>
 #include <linux/fadvise.h>
+#include <linux/writeback.h>
+#include <linux/syscalls.h>
+
+#include <asm/unistd.h>
 
 /*
  * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
  * deactivate the pages and clear PG_Referenced.
  */
-long sys_fadvise64(int fd, loff_t offset, size_t len, int advice)
+SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset, loff_t len, int advice)
 {
        struct file *file = fget(fd);
-       struct inode *inode;
        struct address_space *mapping;
        struct backing_dev_info *bdi;
+       loff_t endbyte;                 /* inclusive */
+       pgoff_t start_index;
+       pgoff_t end_index;
+       unsigned long nrpages;
        int ret = 0;
 
        if (!file)
                return -EBADF;
 
-       inode = file->f_dentry->d_inode;
-       mapping = inode->i_mapping;
-       if (!mapping)
-               return -EINVAL;
+       if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {
+               ret = -ESPIPE;
+               goto out;
+       }
+
+       mapping = file->f_mapping;
+       if (!mapping || len < 0) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       if (mapping->a_ops->get_xip_mem) {
+               switch (advice) {
+               case POSIX_FADV_NORMAL:
+               case POSIX_FADV_RANDOM:
+               case POSIX_FADV_SEQUENTIAL:
+               case POSIX_FADV_WILLNEED:
+               case POSIX_FADV_NOREUSE:
+               case POSIX_FADV_DONTNEED:
+                       /* no bad return value, but ignore advice */
+                       break;
+               default:
+                       ret = -EINVAL;
+               }
+               goto out;
+       }
+
+       /* Careful about overflows. Len == 0 means "as much as possible" */
+       endbyte = offset + len;
+       if (!len || endbyte < len)
+               endbyte = -1;
+       else
+               endbyte--;              /* inclusive */
 
        bdi = mapping->backing_dev_info;
 
        switch (advice) {
        case POSIX_FADV_NORMAL:
                file->f_ra.ra_pages = bdi->ra_pages;
+               spin_lock(&file->f_lock);
+               file->f_mode &= ~FMODE_RANDOM;
+               spin_unlock(&file->f_lock);
                break;
        case POSIX_FADV_RANDOM:
-               file->f_ra.ra_pages = 0;
+               spin_lock(&file->f_lock);
+               file->f_mode |= FMODE_RANDOM;
+               spin_unlock(&file->f_lock);
                break;
        case POSIX_FADV_SEQUENTIAL:
                file->f_ra.ra_pages = bdi->ra_pages * 2;
+               spin_lock(&file->f_lock);
+               file->f_mode &= ~FMODE_RANDOM;
+               spin_unlock(&file->f_lock);
                break;
        case POSIX_FADV_WILLNEED:
-       case POSIX_FADV_NOREUSE:
                if (!mapping->a_ops->readpage) {
                        ret = -EINVAL;
                        break;
                }
-               ret = do_page_cache_readahead(mapping, file,
-                               offset >> PAGE_CACHE_SHIFT,
-                               max_sane_readahead(len >> PAGE_CACHE_SHIFT));
+
+               /* First and last PARTIAL page! */
+               start_index = offset >> PAGE_CACHE_SHIFT;
+               end_index = endbyte >> PAGE_CACHE_SHIFT;
+
+               /* Careful about overflow on the "+1" */
+               nrpages = end_index - start_index + 1;
+               if (!nrpages)
+                       nrpages = ~0UL;
+               
+               ret = force_page_cache_readahead(mapping, file,
+                               start_index,
+                               nrpages);
                if (ret > 0)
                        ret = 0;
                break;
+       case POSIX_FADV_NOREUSE:
+               break;
        case POSIX_FADV_DONTNEED:
-               invalidate_mapping_pages(mapping, offset >> PAGE_CACHE_SHIFT,
-                               (len >> PAGE_CACHE_SHIFT) + 1);
+               if (!bdi_write_congested(mapping->backing_dev_info))
+                       __filemap_fdatawrite_range(mapping, offset, endbyte,
+                                                  WB_SYNC_NONE);
+
+               /* First and last FULL page! */
+               start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
+               end_index = (endbyte >> PAGE_CACHE_SHIFT);
+
+               if (end_index >= start_index)
+                       invalidate_mapping_pages(mapping, start_index,
+                                               end_index);
                break;
        default:
                ret = -EINVAL;
        }
+out:
        fput(file);
        return ret;
 }
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_fadvise64_64(long fd, loff_t offset, loff_t len, long advice)
+{
+       return SYSC_fadvise64_64((int) fd, offset, len, (int) advice);
+}
+SYSCALL_ALIAS(sys_fadvise64_64, SyS_fadvise64_64);
+#endif
+
+#ifdef __ARCH_WANT_SYS_FADVISE64
+
+SYSCALL_DEFINE(fadvise64)(int fd, loff_t offset, size_t len, int advice)
+{
+       return sys_fadvise64_64(fd, offset, len, advice);
+}
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_fadvise64(long fd, loff_t offset, long len, long advice)
+{
+       return SYSC_fadvise64((int) fd, offset, (size_t)len, (int)advice);
+}
+SYSCALL_ALIAS(sys_fadvise64, SyS_fadvise64);
+#endif
+
+#endif